


symbiosis

by kurooos



Category: Voltron: Legendary Defender
Genre: Anal Sex, Dubious Consent, Kabeshiri, Lance is trapped and he isn't too sure if he likes it or not but either way he's gettin dick, M/M, Rough Sex, Scratching, Sex Pollen, Spitroasting, Stuck in a wall, Stuck in the wall, gosh how do i tag everything in this
Language: English
Status: Completed
Published: 2017-03-29
Updated: 2017-03-29
Packaged: 2018-10-12 10:30:26
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,874
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10488861
Author URL: https://archiveofourown.org/users/kurooos/pseuds/kurooos
Summary: There's a fungus infection on the ship but despite this, Keith really really wants to give Shiro a surprise birthday gift. He's worked so hard on it, and so has Lance. But maybe the fungus should have been taken care of beforehand....





	

**Author's Note:**

> this is for jaspurrlock's [wonderful art of Shiro fucking Lance in a wall](http://jaspurrlock.tumblr.com/post/157876900262/happy-fucking-birthday-shiro-xd-in-other-news), that's literally all this is for

"We're in space. Dealing with critical matters and saving civilizations. We literally don't have days to go off of or follow, you didn't have to do anything..."

"It's your birthday, Shiro! How could I _not_ get you anything?" Keith held out the soft black ribbon in his hands, watching Shiro in front of him eagerly.

Shiro was a little more than suspicious; Keith usually gave gifts upfront, and nothing ever bigger than what could fit in his hands.

So now, with Keith telling him his gift was stationary, that Shiro had to go to his gift and not the other way around, he was getting worried. More worried on top of the fact that they really should be focusing on the outbreak of some alien fungus in the castle. It was a serious matter, not one that should be brushed aside for birthdays.

"Keith. We really aren't supposed to be wandering around. I know this is important but Allura said we needed to stay in our rooms for a while until she could scan the entire ship for-"

"Shiro," Keith cut him off, stepping forward and putting a hand on his shoulder "you trust me right?" After having Shiro nod, he continued. "Then you know I would never put you in danger, right?" Another nod. "I asked Allura to scan some areas beforehand; it's safe where we're going."

With Keith's reassurances, sounding gentle and confident, Shiro couldn't deny Keith anymore. He sighed, finally ducking his head.

"Fine, then. I trust you." Shiro closed his eyes after seeing excitement sparkle in Keith's own. Moments later he felt the blindfold go over his eyes, assuring he couldn't peek at where they were going or his supposed gift too early. Keith took Shiro's arm gently, beginning to walk without so much of an affirmation from Shiro.

It wasn't long before they were at a standstill, Keith telling him to not move while his footsteps drifted a ways ahead of them. Shiro stood there impatiently, ready to ask Keith if he could take the blindfold off when suddenly he was being guided forward, Keith's hands taking both of his own.

"Do whatever you want, alright? Lance and I worked hard for this, it took us a long time to plan for." Keith whispered, like they were sharing some secret. Shiro blinked in confusion, eyebrows drawing together when Keith guided his hand down and his fingertips touched warm skin. Curiously, Shiro flattened his hand and slid his touch up. A muffled, barely there moan floated to his ears and he stopped, there was no way that Keith would- that this...

"Keith..."

"Don't worry, Shiro. Remember? Don't let our hard work be for nothing."

Keith said, softly and holding a threat under his tone. Finally, his fingers went behind Shiro's head and undid the blindfold.

The first thing Shiro saw was the wall, right there in front of him. He was rather confused until he looked down, saw the messy words markered onto the wall: Happy B-Day Shiro!!!

He felt his chest grow tight as well as his pants. Those words weren’t what made Shiro's throat close up, no no. The dark skin directly under those words did.

It was obviously Lance, or really his ass, but it was still distinguishable that the muscled legs and round ass presented to him couldn't have been anyone else.

He saw Lance's hands, somehow stuck next to his hips, curled into gentle fists. Shiro's next immediate thought was how they got Lance in the wall like this, and if he was okay.

Keith's hand on his shoulder startled him. In shock, Shiro turned back to look at Keith, who was now grinning, hiding how nervous he really was.

"You like it?" He asked meekly, eyes darting down over Shiro's shoulder to look at Lance.

How was he going reply to that? What should he say? What _could_ he say?

Shiro's silence didn't stop Keith at all; his hands smoothed over Shiro's hips and then up to his chest, beginning to unzip his vest. He rolled up on his toes, pressing in close behind Shiro to kiss him.

"Don't wait," Keith mumbled, lips warm against Shiro’s, "he's ready for you."

Shiro's attention shifted, turning back to look down at Lance. He took a hand and grabbed under a soft cheek, thumb rough in pulling it to the side. Shiro almost groaned at the sight. Keith had obviously done some work here. The simple silver buttplug inside of Lance looked small, practically slipping with lube, enough for it to drip down to Lance's balls and then lazily to the floor. The surrounding skin glistened with the slickness.

"God, Keith. How did you even get him like this?"

Keith gave no answer, instead his hands continued to undo the clothes Shiro had on, already palming between his legs, getting him interested. But damn if he wasn't interested the moment the blindfold had come off. What if someone came around and saw them like this, he suddenly thought? What if Allura checked the video feeds in the control room and saw them, they were out in the middle of the hallway. Knowing they could get caught just added to the thrill, made Shiro's blood pump faster; it reminded him of the days back at the garrison and having to sneak around teachers and guards.

Shiro's head fell back with a groan when Keith finally wrapped his fingers around his cock, thumb swiping over the slit of his cock to smear the pre-cum beading up there. Shiro braced his prosthetic arm against the wall, grunting as he thrusted his hips forward into the tight circle of Keith's hand. He felt lips on the back of his neck, a soft touch that he's felt more than enough times in bed before with Keith. Keith was holding back, patiently waiting for Shiro to do something, to tell him if he was okay or not.

"This is incredible, Keith." He sighed, hastily using his free hand to take hold of the plug inside Lance and twist it, gently trying to ease it out. He wanted to be inside of Lance. Now.

He and Keith had talked about including the blue paladin in their relationship for quite some time. Shiro couldn't deny the warmth Lance made him feel in his chest, especially not when Lance blushed and preened over every 'good job!' And 'nice, Lance!' that he got from the leader.

And here he was, dripping wet and ready to be fucked. With a final twist he eased the plug out of Lance and dropped it to the floor, fingers dipping into the soft and puffy hole before him, earning him a barely audible whimper.

Lance was incredibly hot inside, smooth and fluttering around his teasing fingertips. Lance's hands twisted softly next to him but it seemed he couldn't move them anymore than that.

Keith bumped up behind him, ground the hard tent in his pants against Shiro's ass. "Go on, Shiro. Fuck him."

His voice sounded rough, needy as he kept egging Shiro on close and closer. And really, who was Shiro to say no to that. He slipped his fingers free, using the lube left over on his skin to slick his cock before stepping in closer. Keith never let go, continued to pump him smoothly at the base of his cock while Shiro's thumb guided the head into Lance. His groan came back to him, higher and muffled on the other side of the wall.

"Holy- oh _fuck_ -"

The small breathless voice from behind the wall was tight. Shiro didn't know why he didn't stop and check on Lance. All he knew was his body suddenly wanted more, wanted to be fully buried inside of Lance. Keith's hand moved away when he thrust forward and Shiro slipped his hand off the wall to pull on Lance's hip and grind them closer together.

Keith was finally pulling off the rest of his clothes, interrupting Shiro momentarily to get his shirt off before rewarding him with a slap on the hip, pushing him into Lance more. The action made Shiro jump with a surprised grunt, but he received the message clear enough.

He began to thrust slowly, unsure of how well Keith had stretched Lance but the plug was a good indicator to Shiro that the job was done well. His hips picked up speed, encouraged by Keith's wandering hands over his chest and gentle, possessive nips and kisses over his shoulder and nape.

Shiro felt mindless with each thrust, brain stuck on one track of fucking Lance until he was satisfied. Of course that should have spread warning bells on the entire spectrum, but he was too far in to really think about it. Not now, not as he pulled Lance's hips up and got a shout in response.

"Have fun with him. Happy birthday." Keith whispered, finally putting something over the top of Shiro's head before he was leaving, footsteps fading down the hall. The small string dug in under Shiro's chin and with a breathless laugh he realized it was a party hat. The ridiculousness of it distracted him from wondering where Keith was off to.

"This is quite some gift you two put together."

He says, picking up his pace. Lance's feet shift on the floor, legs slightly parting more as Shiro fucks into him. He's rough and careless, something primal in his head telling him to fuck Lance hard enough he'll feel it later, that he'll have marks. Marks Keith will see later, be able to see how good Lance got it.

Lance moans from the other side, speaking between gasps.

"Th-this isn't what I- nngh! Expected when- _aH!_ When Keith asked if I would p-pitch in for a-ahh- a birthday present!"

The end of his explanation tapers off into a keen, Lance's knees wobbling dangerously as Shiro grinds his cockhead into his prostate. His fingers hold onto dark hips tighter, giving him a better hold as he fucks him harder, knowing that Keith planned for this. The two put so much loving preparation into this, all for him. Shiro grins.

"It's a wonderful gift, Lance, thank you." He chuckles breathlessly, already feeling his orgasm coiling low in his gut as Lance tightens around him. For a moment Shiro's vision tunnels and goes blue, fading out to a dark blurry mess. His heart begins to race and something kicks back inside of him. Distantly he's aware of Lance trying to tell him to wait when Shiro starts to pick up the pace, that he needs to have a break. His pleas fall on deaf ears. Were Shiro more attentive, he would spot the dull glowing gunk crawling down his arms, wishing to spread and infect Lance as well. But Shiro is too far gone, chasing his pleasure alone, grunts spersed between the steady hard rhythm of skin slapping against skin.

Lance suddenly cries out from the other side, legs snapping closed as he cums against the wall. His hands clench and try and yank themselves free but the wall is sturdy around him, not allowing any movement or freedom. It must be uncomfortable, not that Shiro cares at this moment. Not when Lance clenches around him and every shudder and jolt makes Shiro hotter. His forehead presses into the wall as he grunts, grinds his cock into Lance's trembling heat and cums.

"Sh-Shiro!" Lance cries out, surprised at the sudden slippery touch on his sides, unable to think about the jets of cum being pushed into him. The fungus crawls over his skin curiously, looking for a place to settle. Lance barely gets those few seconds to become worried about what is _crawling_ on him because Shiro isn't done.

Hearing Lance behind the wall has Shiro’s cock twitching inside of the stuck paladin. He grinds against him gently but firmly, teeth gritting. He gulps lungfuls of air, feeling as if he'd ran a mile.

Shiro's hands move, palming Lance's round cheeks before pulling them apart to see him stretched around his cock.

Shiro pulls his hips away, teases the head of his cock out slow enough that Lance whines for it, twitching, hips raising up as much as the wall allows him. As much as Lance is struggling with worry and a range of other things, the heat settling in his skin is unbearable, getting worse the longer he’s empty.

"God, Shiro. _Please_..."

Shiro hums and hooks a thumb inside of Lance, gently spreading him so he can watch as his cum trickles out slowly.

"Want more?" He inquired, cock twitching with the thought of getting back inside Lance. It takes the blue paladin a while to reply, maybe he forgot Shiro can't see him nod.

"Fill me up, please, Shiro. It hurts inside. I can't-" the blue paladin cuts himself off with a stifled whine, feet shifting restlessly as he wiggles his hips, tempting Shiro. Small drops of blood drip to the floor from his hips as Shiro digs his nails in, unable to stop from plunging his cock back into Lance. He's quick to set a punishing rhythm, accidentally smearing blood over the curve of Lance's back when he pushes there to angle Lance better. Lance moans and gasps for _more_ , _deeper_ , _harder Shiro fuck me harder!_

In frustration, Shiro pushes his prosthetic against the wall, the desire to have all of Lance in his arms is overbearing. That niggling primal thing inside of him snarls. He tries to pull Lance's hips to get him out of the wall but Lance only yelps in pain, hands clenching. The younger's sobs should be something of concern but they don't register to Shiro.

Shiro's nearing the edge quickly and Lance's rocking hips don't help. He pulls out quickly, not giving Lance a chance to even whimper before he's shoving back inside over and over until Lance is choking on his moans and crying Shiro's name, cock dribbling cum between his legs with each thrust.

Shiro feels a growl build in his chest as he ruts his hips in closer, buries himself deep into Lance, balls aching as he cums again.

Lance's weight leans into Shiro’s hands as his legs tremble, now relying on him to keep his hips up, despite the ache and soreness his muscles feel when Shiro grips him.

Lance has been fucked past the point of exhaustion. He hangs his head, watches sweat drop down to the floor as he pants. If he just had one of his hands free he wouldn't be so tired, his core wouldn't be burning like it was now. It hurts to not have something to lean his weight on, and the edge of the wall digs into his soft skin whenever he relaxes too much.

Shiro hasn't pulled out of him, but he can still feel the warm cum slipping down the inside of his thighs. He's about to complain until he hears footsteps. He turns his head, groaning when he sees Keith walking towards him. His eyes are a bright, unnatural shade of green, identical to the worm-like creature pleasantly curled around his arm and shoulder. He recognizes it immediately as one of the aliens from the infected planet.

Lance squirms, croaking softly for Shiro; he is unsure what good it will do him, Shiro won't be able to find a door into this corridor in time to stop Keith from doing whatever he plans to do. Shiro's hips jump forward, startling a gasp out of Lance.

Keith comes to stand in front of Lance, the grin on his face unfitting. Lines of blue-green matter spans up his neck from under his jacket. Lance curses himself for not realizing Keith being patient zero for the infection earlier. Keith _had_ been the last one to leave the infested planet, he _had_ been slow getting back to the ship, he hadn't been there when they had a meeting about the sudden fungus beginning to spread through the ship's air ducts; and yet afterwards he knew all about the infection and the problem they needed to address.

Keith is no longer himself, Lance easily understands, but his body still shudders at his touch. Keith's warm fingers under his chin sends tingles run down his spine. The sticky gel on his fingers stays coated under Lance's chin, smears over his lips and tongue when Keith shoves his fingers into his mouth.

Lance tries to pull his head away but there's no beating the tight hand now in his hair. Shiro behind him asks a muffled question, Lance can't hear it, too busy gagging around fingers that work too far back into his mouth.

"You will be such a pretty host."

Is the watery voice that trickles from Keith. Instead of feeling afraid for himself, Lance feels needy. He wants Keith. He wants more of whatever he'll give, wants to please, wants the hot itch settling back deep inside of him erased.

When Keith draws his cock from his pants, hastily unzipped and untucked, Lance's mind goes blank. The last thing he remembers before curling his tongue under the head of Keith's cock is Shiro beginning to fuck into him again, and he knows it's going to be a long night.

**Author's Note:**

> I didn't really plan on putting some little plot into this but I always end up doing it anyway lmao, hope you enjoyed! I love hearing reviews!  
> PS this isn't beta'd so, if there are typos, sorry!


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